Diaphragm valve for a carburetor



Aug. 16, 1955 E. E. VAN DERBECK DIAPHRAGM VALVE FOR A CARBURETOR Filed March 10, 1949 JNVENTOR. EI [EUT E VAN UZ'EBMK ATTORNEY Unite DIAPHRAGM varvn son A cAnsUREroR Application March 1'9, 1949, Serial No. 80,755

3 Claims. (Cl. 137-510) The present invention relates to a fluid pressure responsive device, and more particularly to a diaphragm and a diaphragm assembly for use in a fluid control system, such as a fuel metering device for engines, burners and the like.

The diaphragms used in conventional fuel systems are generally secured in operative position by clamping the diaphragm edges between two body members of the fuel system housing. In certain installations, it is diflicult to assemble the diaphragm in place between the two members without distorting the diaphragm and causing wrinkles or waves which prevent proper operation of the diaphragm and thus proper metering of the fuel by the system. It is, therefore, one of the principal objects of the present invention to provide a diaphragm assembly which can readily be installed in operative position free of wrinkles, waves or other distortions which adversely affect the operation of the diaphragm.

Another object of the invention is to provide a readily assembled and easily serviced diaphragm member which inherently so adjusts itself in the installing operation that it remains free of harmful wrinkles or the like and which thereafter readily adapts itself to changes in operating conditions.

A further object of the invention is to provide a diaphragm assembly which can readily be installed in proper operating condition in a fluid control device.

Additional objects and advantages of the present invention will become apparent from the following description and accompanying drawing, in which only one embodiment is disclosed. In the drawing:

Figure 1 is a schematic view of an engine fuel system embodying the present invention;

Figure 2 is an enlarged fragmentary view of a discharge valve assembly showing my diaphragm in operative position;

Figure 3 is a diametric cross-section of the diaphragm showing it removed from the fuel system; and

Figure 4 is a plan view of the diaphragm.

Referring more specifically to the drawing, and to Figure 1 in particular, numeral designates the body of an updraft carburetor, 12 a throttle valve, 14 an air inlet, and 16 a mixture outlet of the induction passage for an internal combustion engine or other fuel consuming device. A controlled supply of liquid fuel is delivered to the induction passage by a metering unit consisting generally of a centrifugal pump 20 adapted to receive fuel from a source at a substantially constant pressure through conduit 22 and to discharge the fuel at an increased variable pressure through conduit 24, fuel metering unit 26, fixed orifice 28, and thence to the discharge valve and nozzle 32. An idle cut-off valve generally shown at 34 may also be included in conduit 24 between the metering orifice 28 and the discharge nozzle. The general arrangement of the fuel metering elements of the present system is shown substantially as disclosed in U. S. Patent 2,443,527, issued June 15, 1948, to Wirth et a1. and application Serial No. 780,368 filed by Wirth "States Patent 0 et al. on October 17, 1947, now Patent No. 2,617,397.

The fuel delivered by the centrifugal pump 20 passes through conduit 24 to the discharge valve assembly entering chamber 42 and then passing through the discharge valve 31 conduit 44 of the discharge nozzle 32, where it mixes with air supplied through conduit 45 to form an emulsion which is discharged into the induction passage on the engine side of the throttle valve. The pressure of the fuel in chamber 42 is regulated by the control pressure in chamber 46, which is separated from chamber 42 by a flexible diaphragm 48 and which is adapted to receive fuel under pressure through conduit 50 from the inlet side of the centrifugal pump. The discharge valve 30 consists of a valve seat 52 and a central disc portion 54 of diaphragm 43, said disc portion moving to and from said valve seat as the pressures in chambers 42 and 46 vary in response to variations in fuel delivery.

The diaphragm 48 is shown in the drawing as a cupshaped element having a highly flexible end portion and a rather rigid side wall 62. The end portion 60 carries a thickened and rather rigid central disc portion 54 which, as explained above, forms an element of the discharge valve. The side wall is adapted to fit over an annular projection or ring-shaped member 64 formed integrally with the discharge valve assembly cover 66 and is provided with a thickened annular portion or rib 68 on the internal side thereof which is adapted to seat in an annular groove or recess 70 formed in the wall of said ring-shaped member. The thickened portion 68 of the side wall has suflicient resiliency to permit it to be readily assembled over the ring-shaped member and into the groove, but is provided with sufiicient strength to retain the diaphragm firmly in place over the said member during the operation of the metering device, and to maintain the inside surface of the side wall of the diaphragm in sealed relationship with the outside surface of the member.

After the diaphragm has been assembled in place on member 64, the cover 66 is assembled in place on the discharge valve body and secured thereto by any suitable means such as cap screws, a suitable gasket 72 being provided between said cover and the body of said assembly. In the present construction, it is seen that the diaphragm can be assembled in place on the discharge valve assembly cover before the cover is assembled on to the body, thus permitting the diaphragm to be fully adjusted and all wrinkles and waves not forming a part of the diaphragm design completely removed before the cover and diaphragm are secured in place in the assembly.

The material from which the diaphragm is made may be of rubber or rubber-like material such as neoprene reinforced with cloth. The present invention, however, is not limited to any particular kind of material provided the material forming the side wall has sufficient resiliency to permit the diaphragm to be assembled over member 64 on the cover and sufficient strength to hold the diaphragm firmly in place during operation of the device.

From the foregoing description of the present invention, it is apparent that a comparatively simple diaphragm construction and assembly means has been devised. Although only one embodiment of my invention has been shown and described, many modifications may be made without departing from the scope of the invention. For example, a valve stem and valve element secured to the center portion of the diaphragm may be used in place of the central disc portion as an element of the valve. Further, arrangement of parts for securing the diaphragm to the ring-shaped member may consist of an annular external rib on the surface of said member and an annular recess in the internal surface of the diaphragm wall, or the side wall of the diaphragm may be arranged to fit inside of the ring-shaped member, the outside surface of the diaphragm wall being sealed against the inside surface of the member. in the event the diaphragm is employed in a system in which high differentials in pressure are encountered between chambers 42 and 46, a band or clamp may be placed around the side wall to hold the diaphragm on member 64.

I claim:

1. A fluid control unit comprising a fluid chamber, an annular ridge-like member extending from one Wall of said chamber, a flexible disc-shape diaphragm having an overturned annular flange embracing the peripheral surface of said member at the junction of said diaphragm with said flange and forming the sole securing means for said diaphragm, a fluid passageway communicating with said chamber within the confines of said member and diaphragm, a fluid passageway communicating with said chamber on the opposite side of said member and diaphragm, and a valve means connected to said diaphragm for controlling one of said passageways.

2. A fluid control unit comprising a fluid chamber, an annular ridge-like member extending from one wall of said chamber, a flexible disc-shaped diaphragm having a single overturned annular flange embracing the peripheral surface of said member at the junction of said diaphragm with said flange, a fluid passageway communicating with said chamber within the confines of said member and diaphragm, a fluid passageway communicating with said chamber on the opposite side of said member and diaphragm, and a valve means connected to said diaphragm for controlling said last mentioned passageway.

3. A fuel control unit for use in a fuel system for an engine, burner, and the like, comprising a chamber, an

annular ridge extending from one wall of said chamber, a flexible disc-shape diaphragm having an overturned annular flange embracing the peripheral surface of said ridge at the junction of said diaphragm with said flange and thereby forming two unconnected fluid compartments in said chamber, one inside and the other outside of said ridge and diaphragm assembly, a passage connected to one of said compartments for subjecting said diaphragm to a variable fluid pressure, a passage connected to the other of said compartments for delivering fuel thereto, a valve operatively connected to said diaphragm for controlling said last mentioned passage, and a passage connected to said last mentioned compartment for delivering fuel therefrom.

References Cited in the file of this patent UNlTED STATES PATENTS 1,064,714 Deegan June 17, 1913 1,289,706 Eggers Dec. 31, 1918 1,333,646 Watrous Mar. 16, 1920 1,922,431 Geyer Aug. 15, 1933 1,924,888 Tatter Aug. 29, 1933 2,074,362 Bowen Mar. 23, 1937 2,098,885 Safiord Nov. 9, 1937 2,102,824 White Dec. 21, 1937 2,208,149 Vernet July 16, 1940 2,211,212 Langdon Aug. 13, 1940 2,272,304 Lohman Feb. 10, 1942 2,509,143 Getchell May 23, 1950 2,545,857 Perkins Mar. 20, 1951 FOREIGN PATENTS 48,105 Germany 1889 808,459 France Nov. 14, 1936 

